The question is, "Cxu Andreo estas la filino de gesinjoroj Lang?"

Of course the correct answer will be in the negative.

This being the case, I see two possible answers to the question.

If the emphasis is on the fact that Andreo is not the daughter but the son of Mr. and Mrs. Lang, I would answer, "Ne, li estas ne la filino. (Li estas la filo.)"

If the emphasis is on the fact that not Andreo but Maria is the daughter of Mr. and Mrs. Lang, I would answer, "Ne, li ne estas la filino. (Maria estas la filino.)"

The placement of the second "ne" is all that is different between the two answers.

Are they both correct, depending on which emphasis one thinks most appropriate? Or is one form more or less used than the other?

It is rare to put the "ne" after the verb, though it is grammatically correct and certainly not wrong to do it. You could theoretically use that "ne" placement to make the distinction that you just outlined but it is rare to do so. It's not to say that people *shouldn't* use the "ne" placement to make this distinction, only that in my experience, people generally don't.

And while I completely see the logic of your distinction here, in practice, if you said to me the sentence about "...estas ne la filino", I would probably assume you were a beginner who didn't yet realize (or an experienced speaker who didn't care) that the "ne" is normally put in front of the verb.

If I wanted to make this distinction (that he is the SON and not the daughter) I might arrange the sentence as something like "La filino li ne estas" or even "Ne la filino estas li". I guess I would rearrange things more drastically to make it more obvious to the listener that I am modifying the order for the purpose of altering the emphasis. If your change is subtle and uncommon, people might not pick up on it.

Frakseno:Are they both correct, depending on which emphasis one thinks most appropriate? Or is one form more or less used than the other?

"Ne" negates whatever follows. "mi ne manĝas", I'm not eating. "ne mi manĝas", it is not me the one that is eating. By negating a verb (the most common usage) you negate the whole (sub)sentence.

mnlg:"Ne" negates whatever follows. "mi ne manĝas", I'm not eating. "ne mi manĝas", it is not me the one that is eating. By negating a verb (the most common usage) you negate the whole (sub)sentence.

Richardson's book agrees with you here, and that's where I got this (page 106, for those following along at home).
:: Hey - at first I thought Cresswell disagreed, but just now I saw (on page 88) that Cresswell also allows for the usage I mention.

Interesa.